In a Long Term Evolution (LTE) network, when congestion reaches a threshold level, the LTE network may invoke access class barring (ACB) to protect the LTE network from failure or shutdown, as well as to provide priority to certain user equipments (UEs) based on the access class of the UEs. For example, access class barring may provide a priority to emergency voice calls (e.g., E911). The LTE network uses System Information Block (SIB) Type 2 messages to carry access class barring parameters.